1. Field of the Invention
The invention relates to a cosmetic emulsion with a special thickening agent that provides a product having improved aesthetics and skin feel.
2. The Related Art
Various emollient creams and lotions have been used to alleviate the signs and symptoms of dry skin. The application of these products help return skin to a normal, moisturized condition by the process of occlusion and humectancy. Historically, a performance dichotomy has always existed, wherein, those ingredients such as glycerin and petroleum jelly found to be effective in the treatment of dry skin, have been cosmetically unacceptable due to their heaviness. This is especially true as you increase the concentration of these materials in a finished emulson product. Therefore, ingredients such as mineral and silicone oils are used by formulators to increase lubricity of a formulation, thereby, decreasing the perception of heaviness related to the materials such as glycerin and petroleum jelly.
U.S. Pat. No. 3,818,105 (Coopersmith et al.) teaches the usefulness of C.sub.12 -C.sub.14 isoparaffinic hydrocarbons as effective skin lubricants in cosmetic preparations. These hydrocarbons were disclosed as being typically admixed with water, monoalkanols, organic esters, polyhydroxy compounds, lanolin, minerals, colorants, surfactants, waxes and perfumes. Example 5 reports a hand cleaner composition whose major ingredients are isoparaffin, oleic acid and nonylphenol (10) ethoxylate, the latter a nonionic surfactant.
U.S. Pat. No. 3,634,265 (Merritt) reports use of a liquid isoparaffinic hydrocarbon as a solvent for skin contaminents in a skin cleaner emulsion. Among the further components listed are a light mineral oil, a long-chain alkanoic acid neutralized with an alkanolamine, an anionic surfactant, a protective colloid and deionized water.
While the aforementioned art has recognized the usefulness of isoparaffinic hydrocarbons, as lubricants or solvents, there has been no mention as to how these materials effect product viscosities. Often one of the more difficult problems in formulating high water system is the search for thickening agents which provide the correct viscosity but do not detract from skin performance properties. Some thickeners provide sufficient body but impart unacceptable greasiness. Moreover, one ingredient frequently renders another physically incompatible resulting in phase separation of the composition. Examples of the aforementioned patents suggest use of rather high levels (greater than 10%) of isoparaffin and no higher than 60% water. There has been no indication as to the affect, if any, of relatively low isoparaffin levels in the presence of a relatively high water concentration. Furthermore, the role of surfactant has not been fully defined in this art.
Consequently it is an object of the present invention to provide a cosmetic emulsion which when applied to the skin will have sufficient viscosity to render it aesthetically pleasing while at the same time avoid a greasy feeling that some thickeners would normally impart.
A further object of the present invention is to provide a hand and body lotion of proper pH and good phase stability.
These and other objects of the invention will more fully be appreciated through the detailed description that follows.